SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58ab134d9725700f7994f6479b05584d3b2f6b4bc1692e499c0951be41fb943c' 
  AND token = '48BoAJpH09V6zaAHX90THm6edYRfZCz1e2t6R1gqcpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}