SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd4a3952c635554d45b486b7f3df22c6d78b51701636e24b1e9175cc16180b61' 
  AND token = 'ezIgaBKvtdG7jMfs72Co+pNFWVPUh8s7OzxRqppycA4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}