SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e83fd862864c299017d95f6d3ccb6aa2bbd29793792836dfca8fcc1d1005ba2' 
  AND token = 'd2PSu4iSg1+7YaX2li5MdFuAiahKMBkCoyuhdddkptY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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