SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27e0c701766d2307ae24b6986679c0ba76893498a8acf6577cbd5c8b06b2bd2f' 
  AND token = '2hvywGx2QjjHFz7hbq2ThwnGjjUZ/aCSBESirCVgK1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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