SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02401ef88bc11db127d52dea875b356812ee4805996ed36b4769c5d6dfb4962c' 
  AND token = 'gnvVwQhxZ3emXUHVMRr+oSS3/9X0yVhs/E+6DYdlOTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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