SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '567532511ea50be30ab66274d60a83960f647bbdf6d9b719edd3a563fd578ddb' 
  AND token = '+6zQOxpM0ZpxD7pud9A2Hnws4KerPG7easKZ+5u90Ow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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