SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa97151879ea2af08b1ed87803b2e5a6ca8788d98ba203f5efabbca1929cf6c2' 
  AND token = 'cYwDiIx+CDirrbx99nPPM/yXd+TKgqqkyDCiD1SUoQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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