SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a348e5161d5b3b2b9523fcd7dff93eaf8d369d97227f3611c3abcc55672b0c6' 
  AND token = 'laz+uTMraAVFYQqOqQc7Om0vREhtIgyGPDTp3hHA4kw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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