SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '911e782379d50ecacdf835ac6cba274334668b3c92d049109dd165f47c1674c9' 
  AND token = 'eTHHXaj4fQqV+v9KVOhmCpQazWcDTIP52BLnlQ8AHFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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