SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4833a5e5e3eb415498ddcd20507a0da94af9a14861ddd6932f93c039370880b3' 
  AND token = 'EZU9bmidxdcHlBWepGHWP3t/T5ibzXxBx6oBQ2pODfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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