SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c85afe1cdd95148764246e12ca0d5e663e1851072ab5e281b306a658eb385c9' 
  AND token = 'f2KBYhjaoGw120C5tP4FXK3z/Tzm2bDWWWDQU52B090=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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