SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab82dd8038040f66661ae54228418542d3cd70dcc37a23e1f415659fc305c2b5' 
  AND token = '1UNgftMsPkIekZ5OztNv3Pdkz6OS7bsRagdJ/MjkFm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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