SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea8c69a2fe0068721cccfd44eceacc2bf91d2332d347b147336b921acd326f9a' 
  AND token = 'aLoLCJ+OhWRTrcaSHI5Y+iW9FRovSyuyf+w31qtb0gA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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