SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec226da2eb470ca7b8765976ed2fd07e99ad062cd2b4371a50d37dded05566ba' 
  AND token = 'LfRHlbYMS7lhx0yAPLYvI6qIxxv2k2nOjr7LhYipVmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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