SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a9889ba8e7327c4270906c858aed2cd8a7fc8847d55a50edd318a8a3264234f4' 
  AND token = '/0rTfoPpvEQNrYrIPFMPASjsnlH9qQJXOqOFlwCl9vs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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