SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91614f7045c10c73adbd9d9846fd8a8ec7484e41402f2c1ab1dd189209edf833' 
  AND token = 'msmlcmxHWbFsGE+GFzNNdpHnJqd6jiHHOE7efMqGmqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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