SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd67563151937f52ae9dd7a1a72b90a33444c5051d4fad7b0916c92f1ba23fd90' 
  AND token = 'lC7lJkoejEKcECCuxf3j+icZZrr4eiF/064Xao15Z5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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