SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7a36e38815beca1dcee6e5a36ada72bae9893585c87db281c2cf37235b500df4' 
  AND token = 'op8LZbDJ6ZBcXzP//FjKuJ7WGAbLnzvQJsxaowKXPP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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