SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fef379a30bc123cca2b5a9e5fbfc93d1f76dbe5978c74cc66a69bd10a8d41d1' 
  AND token = 'ZwXNDqNERWejRBwFN9s1aDwUPts4lfU0phFKh9Tbvcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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