SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d22beb1d969873879fdfa2cabb89feb63c51914ab5aa57e9ee74448fd693bc4' 
  AND token = 'kwi3DN4WT2dnz9iGUX9xPx2MLfaJTiEMsW+fAyNbZDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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