SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44ab65b3f0cd107124eb311d9ed91223923e7966457d5f8605ac2f8036488cd8' 
  AND token = 'LW/pKV/bSe1tr8t3JST0YOQjeF8GKIShZAsAzvVTObg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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