SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ef4f922dfad61486370946f2bff967a072a59e91b84b1bffd28314070544cb2' 
  AND token = 'qKOPK0OOfpj8Hw4/vEHe+U40E0/ZGQbslbozR9IvqLQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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