SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bae4ddcc96e9643861af128dc5b327d081c2b1f71ae3f31e7865ae2eea6f87d3' 
  AND token = 'Nn/degVIDmfTImHV2nhZohHZ5t8E51IXEsrefad7hoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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