SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b619ac60ab873851ee873d3eb11a7dae5baa1fae6909b0593a62c54fd157bdb6' 
  AND token = 'JuK78tW2kCPKYUX5S6WIqEGrrxES6LbdqIBImeaaC4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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