SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05afabe53c6d32ab835f7d020818e2b668f0e3803f2af278f99c76eb87968f0e' 
  AND token = 'bH/51+qA3BOyPb/ElnXmyxMPOZxsagZPeBOBQ2gLAyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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