SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f4b02ab1ba2180fa019156fb849fc5787410afab98a47c04e9001d6e6cf1c6c' 
  AND token = 'XwSMYXf1XwYYQR2opAZYN5AAiPinpZfiMXaiSOCQ3fI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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