SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cfaea3db5d57040ddb38ff695df17f645607fe0cdd5a6f762d61eaffd79acd0' 
  AND token = 'BS0QVVvgV+rbHR6lDf6f203hI7qAQjYO3/NnxWVPETs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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