SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6594515245114005c62205844547cb3eada27a3af8d5f705c22bb2e80207c69' 
  AND token = 'QkAtihcitJcAM/5mU36DnqaRiA37qGKDdWZWsRMWsZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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