SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd71df4cc6f0d38b1485ff5fcf89fa3bd078521a896266c9c21a4fe19695c676' 
  AND token = 'TURsOPaUGPLh9nj3z0MiK7VL9TW/g0CiK+S4CKVR318=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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