SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2ff13a660cbd1e36f840a08d05de4b86224aaaafabef4b310a6bff981010080' 
  AND token = 'xIFy2S8TLmTSS3kR3pVqqBoCEKM9Vqqpe8oookdnCkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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