SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b36fe25d2f685cdcb16f2e8b946c35f09450a86b731ea12c42a37fa31e778c1' 
  AND token = '8VfpsfdmrLMrv89HkwTULz+Jhcm3ATld7VOKuByOysI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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