SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50659884107f66e2776b1c69ffec40112415a93e8ca61a769a00d6351798dd07' 
  AND token = 'Ro+Vc/yFZ/rViOSLwHUieyY8HaWhwytBUNdnFfVpMBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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