SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69c7a958db11f03abb0110c56bdf0a27cfd5f4014f6fe0b8762bc173e8ebb597' 
  AND token = 'TOxB1EYppCvlYMBL8LLZKXg7vE7/oh2QfDeLPmegwR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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