SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b303777a12c19d4df31cd1d9efc5965be04c77c5f6807b0c2c1d8559167424a2' 
  AND token = 'lzYgHuz6xSweXzkfmpvvgatnO+6R1ZozzIm2AndZ/V4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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