SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a21756a025b597f2a458370bfc42471c342169b97a76a2acd1e560ee97fb312c' 
  AND token = 'xbGiUGfnJuTCVxbLL+nqjoMZQo6n5U5vqaP0QsAbeFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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