SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '799159a2734c2f96a8a856fbca9c2ec5be89bb3537cc9ec49fa9bbd4744ef997' 
  AND token = 'FrjGJEmMNLZcngWOYxB8bIpK5BhVGJ15mVdgJLqs6SM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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