SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf057adce915d360e78ec8899fac63b0279e99720297160b6ff10f18adb4355e' 
  AND token = 'j+6hrRXgk/WvQRj9hl2pPZCOGXpr0kZXxctTzJFxNLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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