SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8abf234b3406a3f29a3d8a81eeffe222ee00e4665e804796a96a8554c9d473ff' 
  AND token = 'GjQEMBFQPVvWaM7jTVrjSybCuBqQxF+xJ6JzbIClsug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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