SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '10b8c55a11de34e94e7764b041f382ef33c13038c1f959d18cf22c67f09476a2' 
  AND token = '71xmTiwfYe+EVUUxZBZBrsAyYDdwFPpXKUtXGqPEauQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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