SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '335b1797c18bc1f3a01ba53f9cc51fb1e57fd0fd32547985e492a2226e4e0820' 
  AND token = 'IKqfIRBvC1G6VBJkG2ZJR2eGbD95HlXZsWKkBtNZHdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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