SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e48f8d3297fb64ec260f6c6e1ddaf33c005fb70e90a9b4856133cd6d706d23a2' 
  AND token = 'VrTu5zSz/qg9driTMX0DSIGhjMq2ACLvPGeBnOZ/xHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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