SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98e214b3e22b7900b4f2297766367dbe23ae89efe02f1c0df24d109f3e81a567' 
  AND token = 'NSIpVNw57qHuaegZZ1coQDTisaG+hjnM7fKsvJy54qk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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