SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29af3569d91195f28db7b390fee51a335e109c74012f9a1250e102f126b2d230' 
  AND token = '5YP8RerurpnFfwbBdX6Vl9OwQsz0iI5SNQPnUPcrD3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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