SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cf444967d7cb5046f2916be9f8d82e1568f424bd66ee2ae17169adfa61a366a' 
  AND token = 'dBpe033/CaXHuqLJOllrz94r3ZlansexZyLZ8ycUBU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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