SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8d9996ae9c61e2fb658e674aff9f896255734a7e3dd2f64be8c06c9b67a7190' 
  AND token = 'RWWZdcGesgjluOE33aYlGMWTP9lJOasKlyvZSXqBICM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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