SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42ea073f3269bb796b2cef55148d6b59c2a3bba8979eb8fde7a2e16aa357fcfb' 
  AND token = 'DnBpZwZA0Thj+mFNrLYaCbY26RjLlis8YFzOuGVsm/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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