SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4185f29f6a807f58669d317db438c6ceb1f884b8724f26d5085e0c618866db2d' 
  AND token = 'iHZxsvf7dzQvx5cREnYd6ZyQXrAhBqOX3PnWfmVMIxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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