SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84dd62317672f0ce2eb2ec5ba776ad18bcde71677d83faf0a6bbbe8cac8206ad' 
  AND token = 'EL6+cwXlOsHxQXwpEirGwGY9wX9gFkjkBebWIS5h6wQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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