SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a55eae85966a4e526d00d30c41729a4b9d2ac608ea60b8e6dc8dcc159a9ea30' 
  AND token = 'HdmXyDQZ+/frEaXA5NBcLvuisIrxwnoXPoqp6A+dXlM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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