SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7f0b0a010acfb3e3e8afeca60879fe25720875e64857d14443152db7f8732cc' 
  AND token = 'rMTIUz/k3nJ1HNQK9M7tM1wgA5idz/7V4M8JH8i458c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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