SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9212848570afe4ba2dbd46050733443aa6087a997cac9e4a62c5ada81ed8a43' 
  AND token = 'bqvuOAByw0s/L0hzSG+J9ou9CiBu0fyoSS4xzR95CCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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