SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6713bf9a4fea70c347a5bfb99dbd363f2f608793339a11a90af98af13ea13c8b' 
  AND token = 'Fi0ar3iCdT2L86rc1ratb+1oh9Q3HJAmK1WwxROIIkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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