SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd615e58172c2e9b4c665a534388dd13c547225a423b7ab316289b10c08f3274a' 
  AND token = 'Th+RxjJzujjW4Fla8qKVPHy1hV0W25E1oOLUJdlfyCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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