SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96e90ca1703d5f5f2508adfdfb967c45015e13fbe302ffd3c0f4b466e06d754d' 
  AND token = 'zpNMh8JUN1Sa93SJNPuTxOAPmYpBVdvPg/WJUbIujpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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