SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec371417df255d7e102fb5bb5f2ec55cc65ce0472644e9a29aac837dcaf7a337' 
  AND token = 'pRMPrfghDURiTvwuhPfVl/gvv/UKNp/0Uu2XdAnhJow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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