SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45a3d65e65a563ca2da4b9d841806a42e993704ef7ec8e6297194b7bef90e659' 
  AND token = 'Txi0Ax8ryi2wJ9xsIfvUUbfsngNPP8vTkCI/OxSxBNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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