Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '726ce9b0a9564b2fcd51bda1d5a928301b9fcb503d1751969ea826cada9ef049' 
  AND token = 'fcA4LBvk3+8qzrEy1HKd4DTCQj+gUyULpn1kSgPeWYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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