SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e90395ed72bee6b7ceafa5854b1c656380ec290860d1ed553664ac620bc121f' 
  AND token = '+wzrzNNfTR9ilK9QLivWR/2vXwSEatda8VCug/pZ+XM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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