SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87273274408b6e7e414d6c6f2aadb00e1f6dc730b8997075fbbbf32a13de5449' 
  AND token = 'AOZsmBYrXVna4uJ7BylgKnyW+ucF6I+ZuBl/2O8vBCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00097

JSON explain

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