SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd96934d972b953c4491e37028488d2ab33edfc900b692e99f7ce04a9945c4d51' 
  AND token = 'XZaOMhoirnbl7q5xsUza4DzGVI3HY9gRiO9WfcY21z8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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