SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b88762fa3fdd5b6adc921206635039aef079f938807e7fc2b02f96e30b47d22' 
  AND token = 'Jj8OAFXCznG/Tl+OhdKbkwBqN5XYUFc/K57bBcRl1vk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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