SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e9e713eb2f0bc800283d379c537071610404cd3c2d1f92fcabe65df3ead38cd' 
  AND token = 'K92kQRlu9hKOS5HoRmXBPHrGRnAmlV5+WPRtBjxpoBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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