SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '252fffae487539b909862495b7b1647ce7ae53c161abbb4368311b5d352f96e0' 
  AND token = 'bsGzjAe9UhPHlpTKEvSqilzdl8ZGJaz+PH9JLvV+Pvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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