SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '525914a76dd2d72863cea47ae5c9672734f399fad44fcc6f915560b09f9762a6' 
  AND token = 'RdCmV9TV1+KSX0I8Y4cbwZ+Yos2pnNyHOOklWJ1nwzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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