SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08083b195eb1c7de1cb2c08e6de98b7bdccc3b622e5d22d1e1ea64309d1b442c' 
  AND token = 'PtsW+i1kwOTX8mgGqPrGkG7xiEcMEaeT25P6mjj47HU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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