SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'af36ec9f6075f6265dd2bad2b45eb46a8a48e8a775e8e0af2d4d9e3c68ab0673' 
  AND token = 'g+eKVliZ9Fq3LNBYpSNNuyH8WqVIRNF4iXcj9nhkWw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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