SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b74fc95f4b9e43403fc1a04a4050a248679147fb9a4e9dd02327a7959d8cd861' 
  AND token = '67WWAOp7PEW7Ow/ue0jm2vjXYJX5JxQzgLDgZTw93ms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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