SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93561a3f161d6dc0daaee09948ccbcfa0410b822722d9d6aa696d4d9240f8bd5' 
  AND token = 'lcy0DrKzCHG+20p6bLJqCNxre2HqhXLz52YCXF8q++E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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