SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd45781b0a5ca87343857fa4e1bfcddaf752f19934386002e496d196c8e9c325' 
  AND token = 'HMHbTkdQe90SVpKgRwXPB86cBjTzLF+1HUB1lUc2ZqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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