SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25f14d810af539bebac547f1d09708feb5b690d719a2da0ecaeb0bf58acc4f07' 
  AND token = 'TRN8WS1RLMuIE0wf0x3EaO4AXMEhVI1tBSP7CE2Wedo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}