SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '253af39432e4609d3cd9e5184fa9920046f8d2fbfac6d5ff99e8027f1b082a6d' 
  AND token = 'XI7AE6Qjc6G2GkaHJxPkBK+rw6XuFvzQEwfi6gzvlpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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