SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc196db35390763f3e0e80638c8c8da42f26ffa1e8fb0d7b4298279ee0f06d15' 
  AND token = 'tjgfYZhmHottonbze595lFW4KQ61I23b4xz1ECSp/Tk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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