SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6da9595cf0962248fd1b59453f2b1619ed9aa81ff88eb6b5a7b7c7e38e69e51' 
  AND token = 'KI1M70UtD/eAXdH+KXpySvkZR1FdRKo5ufMv1bsThOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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