SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c0a12a095e0be78c95d40fb01d9b85501327183c1b3394b253d4343a683211e' 
  AND token = 'dxShnFEPmCL5jhXHfNrvXhKM/I8gB6N8477zdKhlVmQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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