SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3ee77836b8f568db7bb91d404012ccfee89ee4dafa332964e263bd724112f3c2' 
  AND token = 'fPuhM2NsDBZbxhWHrZOWOUZiEySUr02YcEiHCkaD0es=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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