SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc36fc3ea89331bf135a6403099b72aa7f8ca111e8fc996b8b6eb84aaa1c9392' 
  AND token = 'Woa8oWdLxxGUboqowqZsb1QV1SzO+sNh59oBi6RgYaY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}