SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '377a841f88d303407567d9e86983db708a4d76d3c3dd19a836e9269e6c89fa99' 
  AND token = 'wfbLPnNDVozwPQlzM4rUhPDQ7tSyBTZZ4mnxfRAoKnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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