SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc39d91da856e4e937658216509358a757f61a2532d7d28e258d064cdd52f990' 
  AND token = '7glSKW/fz/vAfqU/hzMZRi4MFqi7bX+rKh8KO9XfZgk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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