SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6ad6345153bd8cb2c801c578affb25636f4de36ee84655453e69e1f5f8dd925' 
  AND token = '3sGW79EixTW25vlkAlQshZ5/fKKINeN4CSi7vAX6taA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}