SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '675cbd6a7784c77ad131df57e1c06ca08723dfec2cfd9f34e332234d52bd62d7' 
  AND token = 'yMQIXvQ0VZBduPDrlXGbkgZQuz/sw1OWw828Hl4Xf3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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