SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '702ccb556acc50dc9e9bb1d24cb54cea973556e034fe0137fedf7624628e9710' 
  AND token = 'Ub7UNc9DdVIXRHnqTv0ZKRpvjFImlXwUq5hMDdGq2/Y=' 
  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"
    }
  }
}