SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79459083d53f108803f081a32e3889b1f45066e8e7d9d81655e29a3a23ba2d48' 
  AND token = '0Wbmbm0WLJlquTnK6tGRNYHBXwS4ICbm+z6+LmsFejM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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