SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1544b194bb039ce37c3c58a543419832604af02af94c83dd602edf2db0586a1c' 
  AND token = 'cAC1OdSQv6ofmLfzfG8rvOVf7KMzLLdNf6qr80rgB+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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