SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '144f6ae8151c8261af6fca8dcaa1e90531342ec03d04ac4208e35b90369802d2' 
  AND token = 'VIyLVaBc2BMAY1WOKIsesPMNKTps9hMPMm3QBvUzoU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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