Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6a15bb0d041ca86c09f0a1eb5f9fece9d379df5a68d3d938e1c1655e4acd2f0' 
  AND token = 'ZydGYKiIWyKqWy+3yZ8VJkmDRNoQ2aWfrRc2y2eW/zA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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