SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b6899f7221e6f2531132457907a29ac7107d6c90ddda78f11315467ed6a5dd2' 
  AND token = 'k+lQEKhjg4CqOgNzwHnDU8lmKST5kW8DQMiOUtgZRX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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