SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f36a7ac5660058ff31cb6e6836ea79e48a221d64127eb68a790f1d49d72a596a' 
  AND token = 'SmRqgZfoXsKqAsxpDBeEdPgKgBW+Lfpz/i/TZvuMStU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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