SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d795de890e0b30820b5633022bb448d35a3015f927875ff9099cdc93577b09f' 
  AND token = 'LwkrAKQNZ4N2bJhi9jGEiyxIK2HK/2YHRLhfBUwjBz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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