SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64419b3b48c5d19228c628096a2378c0d29e103e48595d718e8914dd73c929eb' 
  AND token = 'jO3sFsapw9cUuar6oZqr68FzSXWdG9VclKPnYUtjT44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}