SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd247618bfe434d4404f4f493f3d616369fb06e01d702504e47f2ca902e2a52da' 
  AND token = 'i0YSAzvhhy5y5L+WvDfCounK7l1j70fzHr/gsqLJFsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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