SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3822e213c932a932c67a2bcb3e016a7218fe9e6f3b36ed2fb2d623e7bc1745cb' 
  AND token = 'tG1pYSyeAiuboK1PZ4Kg3wvFAzybJxBcijtViay8bb0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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