SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cefa0ae7f98b57422d9661ad3c93bab84fcfcb53ca1647e3d242abe80506c0c7' 
  AND token = 'ddPCnqj5ExfOq201o5EiD4OcYyIile1jo5yZe1u+/dU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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