SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f06af33ded8f04ecba53d006f546d923423521d744d3b22c3e29258e2c22550d' 
  AND token = '2U1BhcJBheAMtI3c7ndG/aFyUESRFwBIfZTH7J8CX+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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