SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '99e9b038abde8cf7fba648351981585f2846e9fc2baaaafa2883f738f5943240' 
  AND token = 'sx9iN0Q9yax0tb2C4mb8XlA5wwRI63lHFgoi5SfyWi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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