SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8808e24105512e7adfb97b465c7aa3ce4565adbcb5fd0f0fe20fd3885c78d9a' 
  AND token = 'qbwCtglfFjP+j3j4+BnC/zuYEntE7gsyg13zpmc9Xwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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