SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fe09ec9a9eea1acadc51948d2d0ac379ef8039bb5db3c9aa13c5f0f379f40b85' 
  AND token = 'pwj8hD5gbsNuyx0fMLPZzfxw8hmDnzwR8LerGQGzeN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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