SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fdbad1f85826dd220fa12c76abd2c154ecf774797f784ce939e1773f2f5816e' 
  AND token = 'O0nP6FSS52oxS5QMv3AXRPs+BWuidVOj4V2o+fgn5iA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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