SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52426ea894ae72821260245d658432b7b58a9d83dd8a6773e98d27ed0d72c4d2' 
  AND token = 'O5munc2uIzzl1ZNysTtIIh3DsOjJomiqIgObVM9/V2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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