SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bc00aa4af9eaedf589acb41b0dcbff00d338ddc09df09a870a34a48a12ae08e8' 
  AND token = 'gIBWyLteJ7dH7DhUNbYQ6BQLf48RQNQB0nZ+QQ9p7CY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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