SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3ae6791126135eb6f6ce98bac5f42e7d8629ca93ff530672afcde49e0c3c4243' 
  AND token = 'rPoeoLHaOJXRY9SPe6F3svBrE4y9sKpsWxrpA9x9M0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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