SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7624b816d846c08bfb87e464d94c1ebf9cc0a9612f5c46245bc55959378aa2b5' 
  AND token = 'PREzJhR4JxtMyncRGqfh3ls5B3m/wZtYEbZiIoGrTDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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