SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ceb34b60a5c4646bfb6ce5a8d29a0bdb241388f166bffd32bfb263a56ffea30' 
  AND token = 'DplEAY4LBIm7QuYLPSorLJCQUgIQq0B4pNG7Ba1Ne8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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