SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4d238546830a701befef70f945198fc16a4a2166802295979afa54e02fee659' 
  AND token = 'PfZmjvtHPD2w0F3tb+RF/KfOiEGcA9V0+75oCd9Wapo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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