SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2759c7ef919b26cfffff6da8cf41cf878ab7ea8348c09f2003acb0760c2ff821' 
  AND token = 'TiyRE0x59Vq1hb9xbKEm6M/xlykfjs8XEu6ZoNKNHN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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